But your DK40 doesn't whine much does it?. At least my DK35se hardly whines at all. Near non existent. Only a bit in HI range, which I hardly ever use.
I think the smaller the tractor the larger the whine. I think it has to do with forcing hi pressure oil thru smaller passages.
Think that most complaints I have heard were from smaller tractor owners but I still have had a few moderate sized machines that had a whine.
When I was test running tractors before final decision on the Kioti how much overall noise was one thing the wife kept reminding me of. You see I can deal with the whine almost any day of the year but it drivers her nuts.
Still I haven't had to deal with a whine from a gear or shuttle yet so if someone is really bothered by it go with a shuttle.